Coccidiosis is caused by a one celled parasite of the genus Eimeria. There are 7 strains of Eimeria that can affect chickens and 4 that affect turkeys.

Chicken Coccidia species: Eimeria acervulina, Eimeria maxima, Eimeria tenella, Eimeria necatrix, Eimeria mitis, Eimeria brunetti, Eimeria praecox

Turkey Coccidia species: Eimeria adenoeides, Eimeria meleagrimitis, Eimeria gallopavonis, Eimeria dispersa

The life cycle takes 4-7 days to complete. An active outbreak begins when a bird picks up active oocysts (a capsule with a thick wall protecting the parasite). They sporulate (become infective) when moisture (if bedding is damp to the back of your hand, there is enough moisture for sporulation), temperature (72 degrees F) and oxygen become conducive to growth, which can be as short as 2 days. The oocysts imbed in the intestinal wall and feed off of Thiamine. Once infected, birds can shed oocysts in their feces for several days to weeks. Aside from feces, oocysts can also be spread by insects, dust, wild birds and humans who have oocysts on shoes and equipment. Oocysts can survive up to 600 days in the soil and are killed by either freezing or very high temperatures.

Coccidiosis usually only affects young poultry. Outbreaks are most common between 3 and 8 weeks of age as Coccidia takes time to build to dangerous levels. But birds of any age can become infected if they have never been exposed and allowed to build a natural immunity.

Coccidia are species specific, so Coccidia that affect chickens cannot affect any other animals and vice versa.


  • Droopiness
  • Lethargy
  • Loss of appetite, feed digestion and efficiency
  • Poor weight gain
  • Loss of yellow color in the shanks
  • Pale combs and wattles
  • Ruffled, unthrifty feathers
  • Huddling, acting cold
  • Blood or mucus in feces
  • Diarrhea
  • Dehydration
  • Death


  • Amprolium – does not treat all strains of Coccidia, there is known resistance and prescription medications may be required if there is no improvement in 3 days.
    • Corid or Ampro-Med. Corid is available in powder or concentrated liquid.
    • Liquid Corid – 8cc per gallon of water
    • Powder Corid – 1.25 teaspoons per gallon of water
    • Zero egg withdrawal
    • May need to supplement with a product that contains Thiamine after finishing treatment
  • Sulmet
    • 1 ounce per gallon for 2 days, then 0.5 ounces per gallon for 4 more days
    • If no improvement in 2 days, contact veterinarian
    • Do not hatch eggs until well after the egg withdrawal period to avoid adverse hatchability
    • 21 day egg withdrawal
  • Sulfadimethoxine – only treats Eimeria acervulina and Eimeria maxima
    • 0.5 ounces per gallon drinking water for 6 days – chickens
    • 0.25 ounces per gallon drinking water for 6 days – turkeys
    • 21 day egg withdrawal
  • Natural remedies such as Raw Milk, Yogurt, Apple Cider Vinegar, and Probiotics are not useful as Coccidia do not complete with bacteria in the gut so beneficial bacteria and other microbes will not eliminate coccidial development


  • Adequate floor space for chicks while in the brooder (one square foot per chick)
  • Place waterers and feeders level with the backs of the birds to prevent them from defecating in them
  • Keep birds from roosting on or above waterers and feeders
  • Clean waterers and feeders frequently
  • Keep older birds away from younger birds as older birds are carriers
  • Add fresh bedding/litter or rake frequently to keep oocysts covered
  • Proper ventilation
  • Keep bedding/litter dry – remove damp/wet spots ASAP
  • Keep feeders full to minimize birds from scratching around in bedding/litter
  • Disinfectants are not effective
  • Deep litter method takes approximately 6 months to produce beneficial organisms that “eat” coccidia
  • Medicated feed – this prevents development of natural immunity
  • Vaccines – need to be given at the hatchery or by one week old. The vaccines can cause coccidiosis as they are not attenuated (weakened). They can also cause necrotic enteritis by 16/17 which needs to be treated with antibiotics


Parasite Management for Natural and Organic Poultry: Coccidiosis


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